There is involved a clone based on the principle of a legendary RB-80 designed by Reinhard Buchaly which has many other well-done clones i.e. e.g. EDO, Tourill, RON, Habanero etc.
At first, we would like to point out that we made this device for ourselves since we previously owned some SCRs, however, some failures such as broken central head, buckles falling apart, not working oxy sensor and composite material falling apart on exposed places and even highly oxidizing aluminium plate as a result of some sea diving made us start designing our own rebreather within our team which could resist not only to salt water, but also to quite demanding conditions in the Hranice Karst.
Material: This rebreather is manufactured in two versions with the only difference i.e. material: the first one is made in a standard black plastic, the second one we are most proud of is ALL made of DELRIN, i.e. material which is one of the most durable and tough materials we know and which is noted for its low deformation, minimum absorptiveness, great thermal insulation and the like. Unfortunately, it is one of those most expensive, which is reflected in the price. The SCRUBBER is made of delrin as well, in white colour. It is a design jewel with its rounded patented head and slots for easy fixing of tanks. We are really proud of it, indeed.
We use no PVC tubes (grey PE), toilet pipes or other cheap plastics which were used in the legendary RB-80 itself, in combination with other kinds of plastics or any other cheap components. Why? The reason is prosaic, each plastic is characterized by different qualities, absorption rate, thermal expandability, it reacts differently in various environment and thermal changes, e.g. when diving emergences (Heviz, Hranice Abyss, suddenly changing temperature resulting from sea streams and the like). Why not composite materials? Simply said, bad practical experience. Composite materials (such as carbon fiber composite) are really great, but they split off on exposed places, it is necessary to repair them etc. Any other fastening buckles’ adherence was insufficient for us too.
We identified weakness of all SCR rebreathers, we have experienced so far, which is a water trap membrane and valve into a smaller bellow in the central part. It can cause fatal consequences as a result of its deformation, inadequate seal resulting from impurities etc. That’s why we doubled it, i.e. there are two in a line. As far as we know, it is the first and the only SCR rebreather with this improvement.
Bellow fixing made us worried as well, in fact, we disliked bellows screwed through with many screws with us being unable to check the bellows shape, presence of the salt after sea dives, pollution, or to do so in a very complicated way. That’s why we invented a very special fixing of the bellows using sleeve nut where we can check the bellows shape within couple of seconds.
Hoses: Endlessly complicated matter for us which really worried us. Having tested many hoses for a long time, we had a special rubber mixture made and hade our order manufactured per order in USA and transported those 250 pairs, which was the minimum amount, to airport in Prague. Our SCR TP can be equipped with famous green Cooper hoses as well which can be covered with our cordura protectors with a golden Tres Presidentes logo on it.
Fixing of tanks: Tanks mounting and removing takes ca 2 seconds, no textile stripes which can cast loose, we dispose of a very simple assembling and removing the tanks directly attached to the RB body, which means no demanding constructions and frames with fishing lines being caught in it underwater when diving wrecks. This well-designed system of two A5 stainless counterparts was adopted from another producer and slightly redesigned.
Springs and metal parts: With respect to non-standard diameters and sizes and even due to our requirements, we have those springs made per order from sea water resisting stainless steel with its grade A5; also any other parts are made from the stainless steel of A4/A5. We found A2 grade insufficient for any sea water diving.
Head: The very first rebreather with its patented round head, which is a very significant design feature considerably limiting water resistance particularly when scootering with a DPV. This head is equipped with an oxy sensor place that could be equipped with your oxy sensor and connected to VR3 computer for example, even if we must admit that we are not big fans for those SCRs with oxy sensors, as we have not good experience with it. The head can be equipped with bayonet mounting system or common locking system with stainless NS buckles.
Scrubber: Made of white Delrin, equipped with bayonet mounting (i.e. no screws, but an ordinary bayonet with no tools needed for assembling, refilling with absorbent etc. – no special instruments needed). The scrubber is equipped with a specially designed spring made per order, 2 stainless A5-steel screens and its bottom tap made of black Delrin is adjusted as far as its design is involved so that it enabled as good gas circulation as possible. It is a detail in fact, but we endeavored to be as precise as possible and improved even this detail.
Tanks: We use as a standard 8.5 BAR 300 BAR tanks, nice and thin tanks being offered by e.g. www.montyshop.com. The tanks exceed a bit the lower bottom edge of the rebreather that’s why the exhaust valve is not polluted and doesn’t work improperly as a result, which we also experienced. Simply said, the rebreather doesn’t stand on its body, but on the lower parts of the tanks.
Switchblock: Standard construction as in the case of other SCRs, we will not make up any revolutionary solution.
Education, i.e. the most important aspect of the whole rebreathers diving philosophy: we are preparing certification within the frame of IANTD for our SCR Tres Presidentes rebreather, textbooks shall be hopefully finished asap. It is necessary to realize that the points at issue related not only to SCR, but even CCR diving are not generally easy and it is necessary to learn many new fundamental things, principles, methods of how to solve crises underwater and the like, so that you could dive safe. Pls. follow our Training section. Minimum requirements for SCR 1st level training course is the Nitrox diver certification in any generally acknowledged system.
Trial Dives: We can present our machine within some dive club or in the swimming pool or, shall you be experienced enough, in a local quarry.
In the end, a short thought. Please do not consider rebreather diving, both SCR or CCR as a something which would enable you to save helium mixtures and thus money only. Any rebreather diving, DIR or not-DIR notwithstanding, is a long-term process requiring continuous self-education, training and is not only fun and entertainment. Our friend prof. Novomesky still emphasizes in his lectures saying „submission mainly!“
We will be very happy to meet you
Have a nice day
David & Martin
© 2008 EDVENS MEDIA / Tres Presidentes / MontyShop / Contact us: scr@trespresidentes.com, ICQ: 260-185-435
